school-level data, Coleman 1966, adjusted variables illustration
> ed = read.table(file="D:\\drr06\\stat209\\coleman.dat", header = T)
> attach(ed)
> cor(ed)
           ssal      whcol       ses      tverb     momed      vach
ssal  1.0000000 0.18113980 0.2296278 0.50266385 0.1967731 0.1922916
whcol 0.1811398 1.00000000 0.8271829 0.05105812 0.9271008 0.7534008
ses   0.2296278 0.82718291 1.0000000 0.18332924 0.8190633 0.9271611
tverb 0.5026638 0.05105812 0.1833292 1.00000000 0.1238087 0.3336495
momed 0.1967731 0.92710081 0.8190633 0.12380866 1.0000000 0.7329859
vach  0.1922916 0.75340081 0.9271611 0.33364951 0.7329859 1.0000000

> edreg = lm(vach ~ ssal+ whcol+ ses+ tverb+ momed)
> summary(edreg)
Call:
lm(formula = vach ~ ssal + whcol + ses + tverb + momed)
Residuals:
     Min       1Q   Median       3Q      Max 
-3.94972 -0.61739  0.06235  0.73430  5.00176 
Coefficients:
            Estimate Std. Error t value Pr(>|t|)    
(Intercept) 19.94857   13.62755   1.464   0.1653    
ssal        -1.79333    1.23340  -1.454   0.1680    
whcol        0.04360    0.05326   0.819   0.4267    
ses          0.55576    0.09296   5.979 3.38e-05 ***
tverb        1.11017    0.43377   2.559   0.0227 *  
momed       -1.81092    2.02739  -0.893   0.3868    
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
Residual standard error: 2.074 on 14 degrees of freedom
Multiple R-Squared: 0.9063,     Adjusted R-squared: 0.8728 
F-statistic: 27.08 on 5 and 14 DF,  p-value: 9.927e-07 

> momreg = lm(momed ~ ssal + whcol + ses + tverb) 

> momregadj = lm(vach ~ residuals(momreg))
> summary(momregadj)

Call:
lm(formula = vach ~ residuals(momreg))
Coefficients:
                  Estimate Std. Error t value Pr(>|t|)    
(Intercept)         35.082      1.333  26.322 8.03e-16 ***
residuals(momreg)   -1.811      5.826  -0.311     0.76    
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
Residual standard error: 5.96 on 18 degrees of freedom
Multiple R-Squared: 0.00534,    Adjusted R-squared: -0.04992 
F-statistic: 0.09663 on 1 and 18 DF,  p-value: 0.7595